Speed changing apparatus



Feb. 7 H95@ H. E. EDWARDS SPEED CHANGING APPARATUS Filed July 24. 1946INVENTOR H/A am 75 [aw/Q05.

Patented Feb. 7, 1950 SPEED CHANGING APPARATUS Hilbert E. Edwards,Mansileld, Ohio, assignor to Westinghouse Electric Corporation, EastPittsburgh, Fa., a corporation of Pennsylvania.

Application July 24, 1946, Serial No. 885,989

\ 4 Claims.

My invention relates to speed-changing apparatus and has for an objectto provide imwherein the ratio of low and high-speed operation of thedriven shaft exceeds the ratio of low and high-speed operation of thedriving shaft.

A still further object of the invention is to provide an improvedspeed-changing mechanism for a washing and centrlfuging machine, whichmechanism is simple in construction and readily adjusted to provide highand low-speed operation of the Washing and centrifuging machine.

These and other objects are eiected by my invention as will be apparentfrom the following description and claims taken in connection with theaccompanying drawings, forming a part of this application, in which:

Fig. 1 is a diagrammatic view of a washing and centrifuging machinehaving my improved speedchanging apparatus applied for the drivingthere- Fig. 2 is a sectional view showing, enlarged, the gearedtransmission mechanism employed in Fig. l: and

Fig. 3 is a section taken along the line Ill-III of Fig. 2.

Reference will now be had to Fig. 1 of the drawings wherein I haveelected to show my improved speed-changing apparatus applied to awashing and centrifuging machine of the so-called horizontal axis type.This machine includes a tub l for containing a body of washing iluid andhaving a rotatable perforate basket Il disposed therein for containingthe fabrics to be treated. The basket il is carried by a shaft I2suitable journaled, as shown at i3 in a wall of the tub I0 and providedwith a sheave Il for the rotation of the basket. During washing periods,the basket Il is rotated at a relatively low speed of approximately 49%R. P. M. in the presence 'of a body of washing water within the tub I0so that the fabrics are tumbled in the water whereby they are cleansed.At the conclusion of the washing period, thev body of water is removedfrom the tub and the basket is then rotated at a much higher speed forcentrifugally extracting water from the fabrics.

The shcave Il is belted as shown at I5 to the driven pulley I8 of a.gear transmission, generally indicated at I1, further reference to whichis made hereinafter. The transmission l1 is proat I9 to the pulley 2i,forming a part oi a twospeed electric motor of any well-understoodconstruction and indicated at 22. The motor 22 may be of the split-phasetype and provided with windings 23 and 24 which respectively provide for21o-pole and four-pole operation of the motor energized vby Sil-cyclealternating current, the motor pulley will be rotated at a speed of 3500R. P. M. and when the four-pole winding 24 is energized, the pulley 2|willlbe rotated at approximately 1750 R. P. M. A suitable switch 23 isprovided for selectively energizing the twopole winding 23 or thefour-polewlnding 24.

Reference will now be had to Figs. 2 and 3, for

a description of the speed-change transmission I1. This member includesa casing structure 23 which houses a chain of gears, the driving pinion21 of which is iixed to and rotatable with a shaft 28, the latterextending from the casing andy being driven by the driving pulley I8.The shaft 28 is suitably journaled, as shown at 29, in the casing 26 andis also supported by bearings 3i disposed Within a sleeve 32 which isxed to and rotates with the driven pulley I6. The sleeve 32 isjournaled, as shown at 33, in an end wall of the casing 26.

The pinion 21 meshes with a gear 34 which is carried upon and drives ashaft 35 suitably journaled in the casing 26, as shown at 36. The shaft35 drives a pinion 31 which meshes with the final gear 38, the latterbeing carried by the inwardly-extending sleeve 32 of the pulley IS.

An overrunning clutch 39 of any well-understood construction isinterposed between the gear 33 and the sleeve 32 to provide a drivingconnection between the gear 38 and the sleeve 32. As describedhereinafter, during high-speed operation the sleeve 32 will rotate at ahigher speed than the gear 38 and at this time the clutch 39 providesfor overrunning of the sleeve 32 relative the gear 38. The overrunningclutch 38 may include a plurality of rollers 4i which are disposedwithin recesses 42 formed in the gear 38. In this type of clutch, as iswell understood, one end of the recesses has a depth greater than thediameter of the rollers 4|; the depth of the recesses progressivelydiminishing towards the other end thereof. As viewed in Fig. 3, the gear38 and the sleeve 32 rotate at all times counterclockwise. Duringperiods when' the sleeve 32 is rotated at a higher speed than the gear38, the rollers are disposed in the deep portions of the recesses inorder to permit such operation. 'Howvided with a driving pulley I3belted, as shown so ever, when the sleeve 32 is driven by the gear 38,

Accordingly, when the motor winding 23 is the rollers 4I are wedgedbetween these members in a portion of the recess of reduced depth.

A centrifugal clutch mechanism, generally indicated at 43 and of anywell-understood construction, is driven by the shaft 28 and effects theclutching of the shaft 28 and the sleeve 32 when the shaft 28 is rotatedat or above a predetermined high speed. At this time, of course. theshaft 28 and the sleeve 32 being engaged. rotate in unison. At lowerspeeds the clutch 43 is disengaged so that the shaft 28 may rotaterelative the sleeve 32. Since the clutch 43 may be of anywell-understood type or construction, I have not disclosed it in detailfor the sake ofclearness and brevity. In the embodiment of the inventiondisclosed herein, the clutch will be centrifugally engaged at speedsabove 1800 R. P. M. to provide a direct driving connection between theshaft 28 and the sleeve 32 and at speeds below 1800 R. P. M. the clutch43 will be disengaged. l The vratio of the diameter of the pulleys 2iand I8 is such that the pulley I8 is rotated at speeds of 1055 R. P. M.and 2110 R. P. M. during four-pole and two-pole operation of the motor22, respectively. The ratio of the gear transmission I1 during periodswhen the pulley I8 is rotated at 1055 R. P. M. rotates the pulley I3 at105 R. P. M. The ratio of the pulleys Il and I4 provides a basket speedof 491/2 R. P. M. During washing periods, the four-pole winding of themotor 24 is energized by the selector switch 25 so that the pulley 2|rotates at a speed of 1750 R. P. M. and the pulley I8 at a speed of 1055R. P. M. At this pulley speed, the centrifugal clutch 43 is disengagedso that the pulley I6 is driven by the shaft 28, the gears 21, 34, 31and 38, the overrunning clutch 39 and the sleeves 32. As set forthheretofore, the basket II and the sheave I4 are rotated at approximately49% R. P. M.

High-speed operation of the basket II and centrifuging of the fabricsare effected by energizing the two-pole winding 23 of the motor 22.Accordingly, the speed of the pulley 2| accelerates from 1750 R. P. M.to 3500 R. P. M. and the speed of the pulley I8 is increased from 1055R. P. M. to 2110 R. P. M. During the early stages of this acceleratingperiod, the speed of the pulley I6 and the sheave I4 increasesproportionately. When the speed of the pulley I8 has been increased toapproximately 1800 R. P. M., the centrifugalclutch 43 is engaged so thatthe pulleys I6 and I8 rotate in unison. Of course, at this time theoverrunning clutch 38 permits rotation of the sleeve 32 relative thegear 38. During the latter stages of the accelerating period, the speedof the pulleys I6 and I3 increases from 1800 R. P. M. to 2110 R. P. M.and the speed of the basket II and the sheave; I4 are increased to 975R. P. M.

Slow-speed operation of the basket may be initiated by deenergizing thetwo-pole winding of the motor 22 and energizing the four-pole windingthereof. As the motor decelerates from- 4 be varied to provide thedesired washing and centrlfuging speeds of the basket Il. Furthermore,other types of variable speed A. C. or D. C. motors, employing speedratios other than two to one may be used.

From the foregoing description, it will be apparent that I have providedan improved variable speed mechanism for drivingwashing and centrifugingor other machines requiring twospeed operation, wherein a relative largeratio of speeds of the driven member is effected with a relative smallratio of speeds of the driving motor. The only adjustment necessary toprovide the various speeds of the driven element is the adjustment .by aswitching means of the speed of the driving motor. Solenoid-operatedclutches usually employed for the variation of speeds in apparatus ofthis general type are obviated with the noiseA and frequent servicingwhich .accompanies the use of such devices. This feature is particularlydesirable in domestic type machines. Furthermore, the apparatusdisclosed herein may be economically produced, as such elements asvariable speed motors and compact centrifugal clutches of the type andsizes shown at 43 are readily available on the market at relatively lowcost. The gear transmission which I employ is of simple construction andreadily constructed.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof.

What I claim is:

1. In speed-changing apparatus, the combination of a gear mechanismincluding a driving gear and a driven gear, a shaft for the drivinggear, a sleeve carrying the driven gear and concentrically arranged withrespect to said shaft, means for rotating the shaft at low and highspeeds, a centrifugal clutch associated with said shaft and sleeve andoperative at a speed intermediate said low and high speeds for clutchingthe shaft and sleeve, and an overrunning clutch associated with thesleeve and driven gear and defining a driving connection therebetweenduring periods when the centrifugal clutch is released and providing foroverrunning of the sleeve relative to driven gear during periods whenthe centrifugal clutch is engaged.

2. In speed-changing apparatus, the combination of a casing, a gearmechanism in the casing including a driving pinion and a driven gear, ashaft fixed to the pinion and extending exteriorly of the casing, asleeve supporting the driven gear and extending exteriorly of thecasing, said sleeve and shaft being concentrically arranged, means forrotating the shaft at low and high speeds, a centrifugal clutch exteriorof the casing and associated with the shaft and sleeve, said centrifugalclutch being driven by the shaft and engaged when the speed of the shaftexceeds a predetermined value intermedlate said low and high speeds,said centrifugal clutch being disengaged when the speed of the shaft isbelow said predetermined value, and an overrunning clutch associatedwith the driven gear and the sleeve and' gg tion of a casing, gearingarranged in the casing and including a driving gear and a driven gear, asleeve carrying the driven gear and journaled in the casing, a shaftjournaled within the sleeve and fixed to the driving gear, means forrotating the shaft at low and high speeds, a centrifugal clutch disposedexteriorly of the casing and associated with the shaft and sleeve, saidclutch being driven `by the shaft and engaged for clutching the shaftand sleeve when the speed of the shaft exceeds a predetermined valueintermediate said low and high speeds, said clutch being disengaged whenthe speed of the shaft is less than said predetermined value forrelasing the shaft and sleeve, and an overrunning clutch disposed withinthe casing and associated with the sleeve and driven gear, saidoverrunning clutch providing a driving connection between the drivengear and sleeve during periods when the centrifugal clutch is disengagedand permitting rotation of the sleeve relative the driven gear duringperiods when the centrifugal clutch is engaged.

4. In speed-changing apparatus, the combination Lof a gear mechanismincluding a driving gear and a driven gear, a shaft for the drivinggear, a sleeve carrying the driven gear and concentrically arranged withrespect to said shaft, a

B variable speed motor driving said shaft and having first and secondelectric circuits selectively energized for rotating the shaft at lowand high speeds, means for selectively energizing the eircuits, acentrifugal clutch associated with said shaft and sleeve and operativeat a speed intermediate said low and high speeds for clutching the shaftand sleeve, and an overrunning clutch associated with the sleeve anddriven gear and defining a driving connection therebetween duringperiods when the centrifugal clutch is released and providing foroverrunning of the sleeve relative the driven gear during periods whenthe centrifugal clutch is engaged.

HTLBERT E. EDWARDS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 784,285 Sturtevant Mar. 7, 1905834,592 gSturtevant Oct. 30, 1906 2,187,835 Martin Jan. 23, 19402,387,216 Hood Oct. 16, 1945

